1. Field of the Invention
The present invention relates to pipe cladding sheet materials. Such sheet compositions are used to wrap insulated pipes. Insulation around pipes is held securely in place by these pipe cladding sheet compositions.
2. The prior Art
Presently, pipe cladding which is being used is made from polyvinylchloride. Although polyvinylchloride pipe cladding is puncture resistant and flexible enough to be wrapped around the insulated pipes, the polyvinylchloride is combustible. Even worse, when the polyvinylchloride does burn, it gives off toxic gas.
It would be useful and even advantageous to have a low cost, more fire resistant replacement for the polyvinylchloride pipe cladding.
To function as pipe cladding, however, certain other requirements should be met. Naturally, the composition being used as pipe cladding should wrap the cylindrical volume without breaking or cracking. The material should be in a sheet form and should definitely be relatively easy to handle and install without breaking, puncturing or flaking off the sheet material. For the best versatility in a commercial product, the pipe cladding should be capable of wrapping around a cylindrical volume having a diameter down to 1.5 inches.
Although sheets could be used as pipe wrapping (cladding) without curl memory, pipe cladding should, in its normal position, have a circular curl and have curl memory, so that when it is unrolled or straightened out of its normally cylindrical position, it will reassume a curled position when it is released. This is referred to as "curl memory". Curl memory makes the cladding sheet go around the circular pipe very naturally. This makes it easy to cover the pipe and install the cladding. Curl memory is thus an important requirement for a pipe cladding composition.
It has been discovered that pipe cladding sheet compositions can be prepared using phosphate ceramic. The compositions provided by the instant invention are thin, relatively light in weight, and non-combustible. Due to the thinness of the instant sheet compositions, rolls of these materials can be easily stored and transported. A minimum amount of space is needed for their storage and installation.